Boston & Maine Diesel Roster (All-Time)

Published: May 30, 2026

The Boston & Maine Railroad pioneered dieselization in the Northeast, beginning in the 1930s and completing the transition by the mid-1950s. Early experiments with internal-combustion power gave way to a diverse fleet emphasizing switchers for yard and local work, road switchers for freight, and cab units for passenger and dual-service duties. Builders included ALCO, EMD, GE, and Fairbanks-Morse, with the roster peaking around 200–235 units in the 1960s before later changes under Guilford Transportation Industries in 1983.

A group of classic Boston & Maine FTs, led by #4204, lead a freight through Greenfield, Massachusetts on September 18, 1955. Photographer unknown, Rick Burn collection.

Switchers arrived first. ALCO HH600/HH660 units (1101–1102, 1934–1938) marked the start, followed by GE 44-tonners (110–114/119 series, 1940–1948, class DS-1a) for light industrial and branchline jobs. EMD SW1s (1109–1132, 1939–1953) and SW9s (1220–1231, 1952–1953) provided reliable 1,000-hp yard power, while SW8s (800–807, 1953) added more capacity. ALCO S-series switchers proliferated: S1/S2 (1940s), S3 (1176–1188, 1952), S4 (1266–1274), and S5 (860–865, 1954, some rebuilt). These B-B units handled everything from shop switching to local freights.

Road freight and dual-service power centered on ALCO RS2/RS3 road switchers (1501–1534 series, late 1940s–1950s) and EMD GP7s (1555–1577/GP7 1563–1571 group, 1950–1952) and GP9s (1700–1749, 1957). Later EMD GP18s, GP38-2s (200–212, 300–317 series, 1970s), and GP40-2s expanded the fleet for modernized operations. These versatile units replaced steam Consolidations and Moguls on secondary lines.

Passenger and high-speed services used EMD cab units. E7As (3800–3821 series, 1945–1946) powered named trains in the iconic maroon-and-gold “Minute Man” scheme. F2, F3, and F7 A/B sets (4224–4268 series, 1940s–1950) handled freight and dual duties, often in A-B-B-A consists. A unique Fairbanks-Morse P12-42 pair (1–2, 1957) powered the lightweight Speed Merchant Talgo trainset.

Paint schemes evolved distinctly. Pre-1944 switchers used black with rectangular heralds. Postwar, most received maroon sides with gold stripes and the Minute Man herald. In the 1950s–1970s, many GP9s adopted the McGinnis “Bluebird” livery (blue hoods, black cab, white stripes), while others went solid blue with variations like interlaced BM heralds. Footboard removal in later years added orange step wells on some units.

B&M’s dieselization reflected aggressive modernization: wartime FT orders, postwar EMD and ALCO purchases, and 1970s second-generation EMD power. The roster proved durable, with many units surviving into the Guilford era or finding homes on short lines and museums (e.g., GP38-2 No. 252 at Conway Scenic). By focusing on reliable, maintainable power suited to New England’s network, B&M’s diesel fleet efficiently replaced steam and sustained operations into the late 20th century.

Alco

Road Number	Model	Builder	Completion Date	Serial Number	Notes
860-865	S5	Alco	6/1954	80916-80921	#864 preserved at the Hobo Railroad/Winnipesaukee Scenic Railroad.
1101	HH660	Alco	3/1938	69082	Later renumbered 1161; scrapped in 1/1959.
1102	HH600	Alco	9/1934	68608	Built as demonstrator #602. Later renumbered 1160. Scrapped in 12/1947 by the B&M.
1162	HH660	Alco	12/39	69232	Sold for scrap in 1/1959.
1163-1164	S1	Alco	7/1944-8/1944	70050, 71662	-
1165	S1	Alco	10/1944	72837	-
1166-1167	S1	Alco	8/1948	75895-75896	-
1168-1169	S1	Alco	1/4199	76153-76154	-
1170-1171	S1	Alco	3/1949	76568-76569	-
1172	S1	Alco	5/1949	76737	-
1173-1174	S3	Alco	9/1950	78318-78319	-
1175-1176	S3	Alco	9/1950	78391-78392	-
1177-1179	S3	Alco	2/1952-3/1952	79539-79541	-
1180-1181	S3	Alco	3/1952-4/1952	79767, 79770
1182-1184	S3	Alco	4/1952-5/1952	79771-79773	-
1185-1188	S3	Alco	5/1952-6/1952	80051-80054	#1186 preserved at the Hobo Railroad/Winnipesaukee Scenic Railroad.
1260-1262	S2	Alco	5/1944	72060-72062	-
1263	S2	Alco	6/1945	73376	-
1264-1265	S2	Alco	7/1945	73595-73596	-
1266-1273	S4	Alco	8/1950	78021-78028	-
1274	S4	Alco	9/1950	78319	Rebuilt from S3 #1174
1280-1281	S5m	Alco	6/1954	80916-80917	Rebuilt from S5 #860-861.
1282-1283	S5m	Alco	6/1954	80921, 80918	Rebuilt from S5s #865 and #862.
1501-1504	RS2	Alco	3/1949	76648-76651	-
1505-1509	RS3	Alco	4/1954-5/1954	80732-80736	-
1510-1517	RS3	Alco	10/1954	80749-80756	-
1518-1519	RS3	Alco	4/1955	81162-81163	-
1530-1532	RS2	Alco	3/1949	76652-76654	-
1533-1534	RS2	Alco	6/1949	76975-76976	-

Boston & Maine F3A #4228 rests inside the roundhouse in Somerville, Massachusetts on February 8, 1970. Roger Puta photo.

Electro-Motive

Road Number	Model	Builder	Completion Date	Serial Number	Notes
200	GP38-2	EMD	2/1974	73636-12	#212 repainted in Bicentennial colors.
201-212	GP38-2	EMD	12/1973, 2/1974	73636-1 thru 73636-12	Sold to Kansas City Southern.
300-317	GP40-2	EMD	12/1977	776025-1 thru 776025-18	-
800-807	SW8	EMD	5/1953	18200-18207	#864 preserved at the Hobo Railroad/Winnipesaukee Scenic Railroad.
1103-1105	SC	EMC	8/1936	611-613	-
1106-1108	SC	EMC	7/1938	758-760	-
1109-1111	SW1	EMC	1/1939	912-914	#1109 preserved at the Railroad Museum of New England
1112-1113	SW1	EMD	11/1941	1457-1458	--
1114-1116, 1117	SW1	EMD	10/1946	3884-3886, 3895	-
1118	SW1	EMD	4/1949	8321	--
1119-1132	SW1	EMD	7/1953-8/1953	18186-18199	#1125 involved in head-on collision with Central Vermont GP9 #4929 on 10/2/1972.
1200-1201	NW2	EMD	11/1941	1461-1462	-
1202-1204	NW2	EMD	7/1942	1993-1995	-
1205-1207	NW2	EMD	9/1946	3091-3093	-
1208-1213	NW2	EMD	1/1949	7738-7739, 7734-7737	-
1220-1226	SW9	EMD	1/1952	15748-15754	-
1227-1231	SW9	EMD	5/1953	18181-18185	-
1550-1553	BL2	EMD	7/1948-9/1948	5259-5262	-
1555-1560	GP7	EMD	9/1950	12373-12378	-
1561-1562	GP7	EMD	12/1950	12379-12380	-
1563-1571	GP7	EMD	2/1952-3/1952	15786-15794	-
1572-1577	GP7	EMD	4/1953-5/1953	18175-18180	#1577 became Springfield Terminal #35.
1700-1709	GP9	EMD	2/1957-3/1957	23198-23207	1703-1704, 1706, 1708 renumbered as 1803-1804, 1806, 1808.
1710-1726	GP9	EMD	9/1957-12/1957	23208-23224	1717, 1721, 1725-1726 renumbered as 1817, 1821, 1825-1826.
1727-1739	GP9	EMD	4-6/57	23225-23237	#1738 renumbered 1838. #1732 is preserved at the Railroad of New England Museum.
1740-1749	GP9	EMD	7/1957-9/1957	23238-23247	1748 renumbered 1848
1770-1775	GP18	EMD	5/1961	26659-26664	Renumbered 1750-1755
3800-3801	E7A	EMD	9/1945	3339-3340	-
3802-3815	E7A	EMD	6/1946	3341-3354	-
3816-3819	E7A	EMD	7/1948	5623-5626	-
3820	E7A	EMD	4/1949	8475	-
3821	E8A	EMD	1/1950	9088	Sold to Missouri Pacific as #42.
4200A-4205A	FTA	EMD	9/1943-12/1943	1916-1921	Traded in to EMD.
4200B-4205B	FTB	EMD	9/1943-12/1943	1969-1974	-
4206A-4207A, 4208A	FTA	EMD	2/1944-10/44	1975-1977	Traded-in to EMD.
4206B-4207B, 4208B	FTB	EMD	2/1944-10/1944	1994-1996	-
4209A-4211A, 4212A-4223A	FTA	EMD	10/1944-11/1944	1991-1993, 2404-2415	Traded-in to EMD.
4209B-4211B, 4212B-4223B	FTB	EMD	2/1944-10/1944	1997-1999, 2416-2427	-
4224A-4226A	F2A	EMD	10/1946	3085-3087	-
4227B-4228B	F2B	EMD	10/1946	3088-3090	-
4227A-4228A	F3A	EMD	10/1948	5601-5602	-
4227B-4228B	F3B	EMD	10/48	5604-5605	-
4250A-4264A	F2A	EMD	7/1946	3070-3084	-
4265A	F7A	EMD	3/1949	8478	-
4265B-4266B	F7B	EMD	7/1950	12303-12304	-
4266A-4267A	F7A	EMD	3/1949	8476-8477	-
4267B-4268B	F7B	EMD	11/1950	12382-12383	#4268B preserved by the Anthracite Railroads Historical Society as Jersey Central 'D'.
4268A	F7A	EMD	10/1949	9932	-
6000	AA	EMC	2/1935	9932	Streamlined shovel-nose power car for the "Flying Yankee" trainset.

Fairbanks-Morse

Road Number	Model	Builder	Completion Date	Serial Number	Notes
1-2	P12-42	FM	12/1957	17L1060-17L1061	Power cars for the "Speed Merchant", a lightweight TALGO trainset.

Boston & Maine GP40-2s #302 and #314, along with GP38-2 #209, pull into SK Yard in Buffalo, New York arriving from Binghamton on the Southern Tier line on June 12, 1983. Doug Kroll photo.

General Electric

Road Number	Model	Builder	Completion Date	Serial Number	Notes
110-113	44-ton	GE	11/1940	12915-12917, 12943	-
114-116	44-ton	GE	6/1941-7/1941	13092-13094	-
117	44-ton	GE	8/1942	15036	-
118-119	44-ton	GE	12/1947, 6/1948	29076, 29974	-
1100	Boxcab	GE/Ingersoll-Rand	1/1935	11645	-

Plymouth Locomotive Works

Road Number	Model	Builder	Completion Date	Serial Number	Notes
100	JL8	Plymouth	6/1930	3506	-
101	ML8	Plymouth	3/1938	3963	-

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